A low-wear liquid delivery pump

Abstract

This invention relates to the field of hydraulic transfer pump technology, specifically to a low-wear liquid transfer pump, comprising a housing, a rotating drum, a plunger, and a swashplate. An input shaft is located inside the housing, and the rotating drum is mounted on the input shaft. The rotating drum has multiple suction chambers inside, and the plunger is slidably disposed within each suction chamber. The plunger has a ball head with a first branch hole and a second branch hole inside. The swashplate is inclinedly disposed within the housing, and multiple slippers abut against it. Each slipper has a ball socket, and the ball head is ball-hinged within the ball socket. The inner surface of the ball socket has a first balance chamber and a second balance chamber. When the plunger is in the hydraulic stroke, the first branch hole communicates with the first balance chamber, and liquid from the suction chamber enters the first balance chamber to balance the positive pressure on the ball head. When the plunger is in the suction stroke, the second branch hole communicates with the second balance chamber, and liquid from the second balance chamber enters the suction chamber to balance the negative pressure on the ball head, thus extending its service life.

Description

Technical Field

[0001] This invention relates to the field of hydraulic transfer pump technology, and in particular to a low-wear liquid transfer pump. Background Technology

[0002] Swashplate axial piston pumps are commonly used liquid transfer pumps and are widely applied in engineering machinery and hydraulic transmission systems. They rely on the cylinder block to drive the piston and slipper to rotate around the main shaft, and the swashplate constraint enables periodic changes in the piston cavity volume, completing the liquid suction and pressure transfer operations. For example, patent document CN119467267B discloses a piston assembly and a piston pump. The piston pump includes a swashplate assembly and a distribution plate assembly. The swashplate assembly is used to adjust the efficiency of the piston assembly in suction or discharge, and the distribution plate assembly is used to switch the working state of the piston assembly (suction and discharge). One end of the swashplate assembly is detachably connected to the inner wall of the housing assembly, and the other end is detachably connected to the slipper unit of the piston assembly. One end of the distribution plate assembly is detachably connected to the inner wall of the housing assembly, and the other end is detachably connected to the cylinder block unit. A transmission component passes sequentially through the housing assembly, swashplate assembly, piston assembly, and distribution plate assembly, and is driven by each assembly.

[0003] However, in existing plunger pumps, during the oil suction and discharge cycle, the fluid pressure difference creates a significant contact load at the hinge joint formed by the slipper ball joint and the plunger ball joint. Under prolonged high pressure and alternating loads, this hinge joint is prone to wear, thus shortening the service life of the liquid transfer pump. Summary of the Invention

[0004] Therefore, it is necessary to provide a low-wear liquid transfer pump to address the current technical problem of short service life of liquid transfer pumps caused by fluid pressure difference.

[0005] The above objectives are achieved through the following technical solutions: A low-wear liquid transfer pump includes a housing, a rotating drum, a plunger, and a swashplate. An input shaft is located inside the housing. The rotating drum is coaxially mounted on the input shaft and can rotate synchronously around its own axis with the input shaft. The rotating drum has multiple suction chambers distributed circumferentially inside. Each plunger corresponds to one suction chamber and slides axially within a suction chamber along the input shaft, thus providing both a pressure stroke and a suction stroke. An internal flow channel communicates with the suction chambers. A ball head is located at the end of the plunger away from the suction chambers, and the ball head contains a first and a second branch hole, both of which communicate with the internal flow channel. The swashplate is inclined within the housing and fitted onto the input shaft. Multiple slippers abut against the inclined surface of the swashplate. Each slipper corresponds to a plunger. The slipper has a ball-and-socket joint, and the ball head is ball-and-socket hinged within the ball-and-socket joint. The inner surface of the ball-and-socket joint is provided with an annular and independent first and second balance chambers. The second balance chamber is located away from the swashplate relative to the first balance chamber, and the axes of the first and second balance chambers are both perpendicular to the swashplate. When the plunger is in the hydraulic stroke, the second branch hole is not connected to the second balance chamber, but the first branch hole is connected to the first balance chamber. The liquid in the suction chamber enters the first balance chamber sequentially through the internal flow channel and the first branch hole to balance the positive pressure on the ball head. When the plunger is in the suction stroke, the second branch hole is not connected to the second balance chamber, but the second branch hole is connected to the second balance chamber. The liquid in the second balance chamber enters the suction chamber sequentially through the second branch hole and the internal flow channel to balance the negative pressure on the ball head.

[0006] Furthermore, the inner surface of the ball socket is also provided with a first distribution cavity and a second distribution cavity. The first distribution cavity is connected to the first balance cavity, and the second distribution cavity is connected to the second balance cavity. During the rotation of the drum, the plunger will be at the lowest and highest positions of the swashplate, respectively. At the lowest or highest position, the first branch hole is connected to the first distribution cavity, and the second branch hole is connected to the second distribution cavity. The plunger moves from the lowest position to the highest position during the liquid compression stroke. During this process, the first branch hole is connected to the first distribution cavity, and the second branch hole is offset from the second distribution cavity. The plunger moves from the highest position to the lowest position during the liquid suction stroke. During this process, the first branch hole is offset from the first distribution cavity, and the second branch hole is connected to the second distribution cavity.

[0007] Furthermore, the slipper is provided with a first flow orifice and a second flow orifice, the extension directions of the first flow orifice and the second flow orifice are both perpendicular to the swashplate; the slipper is also provided with a first inclined hole and a second inclined hole, the first inclined hole connecting the first distribution cavity to the first flow orifice, and the second inclined hole connecting the second distribution cavity to the second flow orifice; a first secondary damping orifice is provided between the first flow orifice and the first balance cavity, the first secondary damping orifice being used to limit the flow rate between the first flow orifice and the first balance cavity, and a second secondary damping orifice is provided between the second flow orifice and the second balance cavity, the second secondary damping orifice being used to limit the flow rate between the second flow orifice and the second balance cavity.

[0008] Furthermore, the damping value of the first damping orifice is less than the damping value of the second damping orifice.

[0009] Furthermore, a compression spring is provided between the plunger and the inner wall of the suction chamber. The axis of the compression spring is parallel to the axis of the input shaft, and the compression spring has a tendency to extend the plunger out of the suction chamber.

[0010] Furthermore, a third balance chamber is provided between the slipper and the swashplate, and a main damping hole perpendicular to the swashplate is provided through the center of the slipper. The internal flow channel includes interconnected through holes and an inner cavity. The through holes are connected to the first branch hole and the second branch hole, and the inner cavity is connected to the suction chamber. The liquid in the suction chamber can enter the third balance chamber in sequence through the inner cavity, the through hole, and the main damping hole.

[0011] Furthermore, the housing is equipped with a first end cover and a second end cover at both ends along the axial direction of the input shaft. The second end cover has a distribution plate on the side facing the rotating cylinder. The distribution plate is coaxial with the input shaft and has an outlet hole and an inlet hole. The outlet hole is connected to the suction chamber corresponding to the plunger in the hydraulic stroke, and the inlet hole is connected to the suction chamber corresponding to the plunger in the suction stroke. The side of the second end cover facing the rotating cylinder has an outlet chamber and an inlet chamber. The outlet chamber is set to correspond to the outlet hole, and the inlet chamber is set to correspond to the inlet hole. The two sides of the second end cover also have an outlet port and an inlet port, respectively. The outlet port is connected to the outlet chamber, and the inlet port is connected to the inlet chamber.

[0012] Furthermore, both the liquid outlet chamber and the liquid inlet chamber are arc-shaped.

[0013] Furthermore, a central spring is sleeved on the input shaft, and the central spring is located at the center of the rotating drum. The central spring is used to press the rotating drum against the distribution plate.

[0014] Furthermore, the low-wear liquid transfer pump also includes a return plate, which is parallel to the swashplate and connected to the end of the drum. The return plate has multiple mounting holes distributed circumferentially thereon. Each slipper corresponds to a mounting hole and is inserted into the corresponding mounting hole. The return plate is used to press the slipper axially against the surface of the swashplate.

[0015] The beneficial effects of this invention are: The low-wear liquid transfer pump provided by this invention, firstly, during the pressure stroke, the suction chamber is under positive pressure, which causes the ball head to tend to press against the inner wall of the ball socket. At this time, high-pressure liquid is introduced into the first balance chamber through the first branch hole, forming a reverse hydraulic pressure opposite to the positive pressure in the first balance chamber, thereby counteracting the excessive pressing force of the ball head on the ball socket. Secondly, during the suction stroke, the suction chamber is under negative pressure, which causes the ball head to tend to detach from the inner wall of the ball socket. At this time, the second balance chamber is connected through the second branch hole, allowing liquid in the second balance chamber to be drawn into the suction chamber, reducing the hydraulic pressure in the second balance chamber, thereby counteracting the separation force generated by the negative pressure and preventing the ball head from separating from the ball socket. Thus, overall, excessive wear between the plunger ball head and the slipper ball socket can be avoided, extending their service life.

[0016] Second, the second balance chamber is positioned away from the swashplate relative to the first balance chamber. This allows the position of the first balance chamber to correspond to the force position when the ball head presses against the ball socket, and the position of the second balance chamber to correspond to the force position when the ball head separates from the ball socket. This allows for targeted adjustment of the hydraulic pressure at the force position.

[0017] Third, during the hydraulic stroke, wear is more likely to occur between the ball head and the socket. The low damping value of the first damping orifice helps to quickly adjust the pressure in the first balance chamber. Since the second balance chamber is closer to the opening of the socket and is therefore prone to leakage, the high damping value of the second damping orifice can prevent liquid leakage in the second balance chamber and make the pressure changes in the second balance chamber more stable. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall structure of an axial piston pump provided in an embodiment of the present invention; Figure 2 This is a side view of an axial piston pump according to an embodiment of the present invention. Figure 3 for Figure 2 Schematic diagram of the AA section; Figure 4 This is a schematic diagram of the internal structure of an axial piston pump provided in an embodiment of the present invention; Figure 5 This is a schematic diagram of the structure of the second end cover in an axial piston pump according to an embodiment of the present invention; Figure 6This is a schematic diagram of the structure of the plunger in an axial plunger pump according to an embodiment of the present invention; Figure 7 This is a schematic diagram of the structure of the slipper in an axial piston pump according to an embodiment of the present invention; Figure 8 This is a side view of the slipper in an axial piston pump according to an embodiment of the present invention; Figure 9 for Figure 8 Schematic diagram of the BB section; Figure 10 A cross-sectional view of the slipper in an axial piston pump provided in an embodiment of the present invention; Figure 11 This is a schematic diagram of the axial piston pump with the piston in its lowest position according to an embodiment of the present invention; Figure 12 This is a schematic diagram of the state in which the plunger is in the hydraulic stroke of an axial plunger pump according to an embodiment of the present invention; Figure 13 This is a schematic diagram of the axial piston pump with the piston in its highest position according to an embodiment of the present invention; Figure 14 This is a schematic diagram of the state in which the plunger is in the suction stroke of an axial plunger pump provided in an embodiment of the present invention.

[0019] in: 101. Input shaft; 102. First end cap; 103. Housing; 104. Second end cap; 1041. Liquid inlet chamber; 1042. Liquid inlet; 1043. Liquid outlet chamber; 1044. Liquid outlet; 105. Swashplate; 106. Rotary drum; 200. Return plate; 201. Third balance chamber; 202. Main damping orifice; 300. Plunger; 301. Inner cavity; 302. Compression spring; 303. Through hole; 3031. First support hole; 3 032, Second branch hole; 400, Distribution plate; 401, Liquid outlet hole; 402, Liquid inlet hole; 500, Slipper; 5001, Ball socket; 501, First distribution cavity; 502, Second distribution cavity; 503, Second balance cavity; 504, First balance cavity; 505, Second flow orifice; 5051, Second auxiliary damping orifice; 5052, Second inclined hole; 506, First flow orifice; 5061, First auxiliary damping orifice; 5062, First inclined hole. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below through embodiments and in conjunction with the accompanying drawings. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0021] The component designations used in this document, such as "first" and "second," are merely for distinguishing the described objects and do not have any sequential or technical meaning. The terms "connection" and "linkage" used in this invention, unless otherwise specified, include both direct and indirect connections (linkages). It should be understood that the terms "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are used only for the convenience of describing the invention and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as limiting the invention.

[0022] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0023] like Figures 1 to 14As shown, an embodiment of the present invention provides a low-wear liquid transfer pump, including a housing 103, a rotating drum 106, a plunger 300, and a swashplate 105; the housing 103 has an input shaft 101 inside; the rotating drum 106 is coaxially mounted on the input shaft 101, and the rotating drum 106 can rotate synchronously with the input shaft 101 around its own axis, and the rotating drum 106 has a plurality of suction chambers distributed circumferentially inside; the plunger 300 is correspondingly arranged with each suction chamber, and the plunger 300 is slidably disposed in the suction chamber along the axial direction of the input shaft 101, thereby giving the plunger 300 a liquid pressure stroke and a liquid suction stroke; the plunger 300 has an internal flow channel inside, the internal flow channel communicating with the suction chamber, and a ball head is provided at the end of the plunger 300 away from the suction chamber. The ball head is provided with a first support hole 3031 and a second support hole 3032, both of which are connected to the internal flow channel. The swashplate 105 is inclinedly disposed inside the housing 103 and sleeved on the input shaft 101. Multiple slippers 500 abut against the inclined surface of the swashplate 105. Each slipper 500 corresponds to a plunger 300. Each slipper 500 has a ball socket 5001, and the ball head is ball-hinged in the ball socket 5001. The inner surface of the ball socket 5001 is provided with an annular and independent first balance cavity 504 and a second balance cavity 503. The second balance cavity 503 is disposed away from the swashplate 105 relative to the first balance cavity 504, and the axes of the first balance cavity 504 and the second balance cavity 503 are both perpendicular to the swashplate 105.

[0024] When the plunger 300 is in the hydraulic stroke, the second branch hole 3032 is not connected to the second balance chamber 503, and the first branch hole 3031 is connected to the first balance chamber 504. The liquid in the suction chamber enters the first balance chamber 504 through the internal flow channel and the first branch hole 3031 in sequence to balance the positive pressure on the ball head. When the plunger 300 is in the suction stroke, the first branch hole 3031 is not connected to the first balance chamber 504, and the second branch hole 3032 is connected to the second balance chamber 503. The liquid in the second balance chamber 503 enters the suction chamber through the second branch hole 3032 and the internal flow channel in sequence to balance the negative pressure on the ball head.

[0025] Specifically, the input shaft 101 is equipped with a gear, and the center of the rotating drum 106 is provided with a toothed groove. The gear meshes with the toothed groove, thereby enabling the input shaft 101 to drive the rotating drum 106 to rotate synchronously. The swashplate 105 has a certain angle with the input shaft 101.

[0026] The low-wear liquid transfer pump of the present invention, during the pressure stroke, has a positive pressure in the suction chamber, which causes the ball head to tend to press against the inner wall of the ball socket 5001. At this time, high-pressure liquid is introduced into the first balance chamber 504 through the first branch hole 3031, forming a reverse hydraulic pressure opposite to the positive pressure in the first balance chamber 504, thereby counteracting the excessive pressing force of the ball head on the ball socket 5001. During the suction stroke, the suction chamber has a negative pressure, which causes the ball head to tend to detach from the inner wall of the ball socket 5001. At this time, the second balance chamber 503 is connected through the second branch hole 3032, allowing the liquid in the second balance chamber 503 to be drawn into the suction chamber, reducing the hydraulic pressure in the second balance chamber 503, thereby counteracting the separation force generated by the negative pressure and preventing the ball head from separating from the ball socket 5001. Thus, the overall pump can avoid excessive wear between the plunger 300 ball head and the slipper 500 ball socket 5001, extending their service life. Furthermore, the second balance chamber 503 is positioned away from the swashplate 105 relative to the first balance chamber 504. This allows the position of the first balance chamber 504 to correspond to the force position when the ball head presses against the ball socket 5001, and the position of the second balance chamber 503 to correspond to the force position when the ball head separates from the ball socket 5001. This allows for targeted adjustment of the hydraulic pressure at the force position.

[0027] Furthermore, the inner surface of the ball socket 5001 is also provided with a first distribution cavity 501 and a second distribution cavity 502. The first distribution cavity 501 is connected to the first balance cavity 504, and the second distribution cavity 502 is connected to the second balance cavity 503. During the rotation of the rotary drum 106, the plunger 300 will be at the lowest and highest positions of the swashplate 105, respectively. Figure 11 and Figure 13 As shown, at the lowest or highest position, the first branch hole 3031 communicates with the first distribution cavity 501, and the second branch hole 3032 communicates with the second distribution cavity 502; the plunger 300 moves from the lowest position to the highest position during the hydraulic stroke, as shown... Figure 12 As shown, in this process, the first branch hole 3031 is connected to the first distribution cavity 501, and the second branch hole 3032 is offset from the second distribution cavity 502; the plunger 300 moves from the highest position to the lowest position during the liquid suction stroke, as shown... Figure 14 As shown, in this process, the first branch hole 3031 is offset from the first distribution cavity 501, and the second branch hole 3032 is connected to the second distribution cavity 502.

[0028] By utilizing the positional change of the plunger 300 as the rotating drum 106 rotates, the connection relationship between the first branch hole 3031, the second branch hole 3032 and the first distribution cavity 501, the second distribution cavity 502 can be automatically switched, thereby achieving the adjustment of the pressure in the balance cavity. This eliminates the need for electrical control components, simplifies the structure, and reduces costs.

[0029] Furthermore, the slipper 500 is provided with a first flow orifice 506 and a second flow orifice 505, the extension directions of the first flow orifice 506 and the second flow orifice 505 are both perpendicular to the swashplate 105; the slipper 500 is also provided with a first inclined hole 5062 and a second inclined hole 5052, the first inclined hole 5062 connects the first distribution cavity 501 with the first flow orifice 506, and the second inclined hole 5052 connects the second distribution cavity 502 with the second flow orifice 505; a first secondary damping hole 5061 is provided between the first flow orifice 506 and the first balance cavity 504, the first secondary damping hole 5061 is used to limit the flow rate between the first flow orifice 506 and the first balance cavity 504, and a second secondary damping hole 5051 is provided between the second flow orifice 505 and the second balance cavity 503, the second secondary damping hole 5051 is used to limit the flow rate between the second flow orifice 505 and the second balance cavity 503. The first damping orifice 5061 and the second damping orifice 5051 can limit the flow rate of the liquid, thereby preventing pressure changes from causing wear between the ball head and the ball socket 5001.

[0030] Furthermore, the damping value of the first auxiliary damping orifice 5061 is less than that of the second auxiliary damping orifice 5051. During the hydraulic stroke, wear is more likely to occur between the ball head and the ball socket 5001. The lower damping value of the first auxiliary damping orifice 5061 helps to quickly adjust the pressure in the first balance chamber 504. Since the second balance chamber 503 is closer to the opening of the ball socket 5001 and is therefore prone to leakage, the higher damping value of the second auxiliary damping orifice 5051 can prevent liquid leakage in the second balance chamber 503 and make the pressure changes in the second balance chamber 503 more stable.

[0031] Furthermore, a compression spring 302 is provided between the plunger 300 and the inner wall of the suction chamber. The axis of the compression spring 302 is parallel to the axis of the input shaft 101, and the compression spring 302 has a tendency to extend the plunger 300 out of the suction chamber. When the plunger 300 enters the liquid-pressing stroke from its lowest position, the compression spring 302 is compressed; when the plunger 300 enters the liquid-suction stroke from its highest position, the elastic force of the compression spring 302 is automatically released, thereby pushing the plunger 300 out of the suction chamber and accelerating the liquid suction process.

[0032] Furthermore, a third balance chamber 201 is provided between the slipper 500 and the swashplate 105. A main damping hole 202 perpendicular to the swashplate 105 is provided through the center of the slipper 500. The internal flow channel includes a through hole 303 and an inner cavity 301 that are interconnected. The through hole 303 is connected to the first branch hole 3031 and the second branch hole 3032. The inner cavity 301 is connected to the suction chamber. The liquid in the suction chamber can enter the third balance chamber 201 in sequence through the inner cavity 301, the through hole 303, and the main damping hole 202.

[0033] Furthermore, a first end cover 102 and a second end cover 104 are respectively installed at both ends of the housing 103 along the axial direction of the input shaft 101. A distribution plate 400 is provided on the side of the second end cover 104 facing the rotating drum 106. The distribution plate 400 is coaxial with the input shaft 101, and has an outlet hole 401 and an inlet hole 402. The outlet hole 401 communicates with the suction chamber corresponding to the plunger 300 during the hydraulic stroke, and the inlet hole 402 communicates with the plunger 300 during the suction stroke. The suction chamber corresponding to 00 is connected; the second end cap 104 has an outlet chamber 1043 and an inlet chamber 1041 on its side facing the rotating drum 106. The outlet chamber 1043 is provided corresponding to the outlet hole 401, and the inlet chamber 1041 is provided corresponding to the inlet hole 402. The two sides of the second end cap 104 also have an outlet port 1044 and an inlet port 1042, respectively. The outlet port 1044 is connected to the outlet chamber 1043, and the inlet port 1042 is connected to the inlet chamber 1041. In this way, the inlet port 1042 and the outlet port 1044 are directly integrated into the second end cap 104, which facilitates the connection between the pump and the pipeline.

[0034] Specifically, the input shaft 101 is rotatably mounted on the first end cover 102 via bearings, and the distribution plate 400 is sleeved on the input shaft 101 via bearings.

[0035] Furthermore, both the outlet chamber 1043 and the inlet chamber 1041 are arc-shaped. This design ensures a smooth flow transition when the plunger 300 switches strokes, reducing pump flow pulsation.

[0036] Furthermore, a central spring is fitted onto the input shaft 101, and the central spring is located at the center of the rotating drum 106. The central spring is used to press the rotating drum 106 against the distribution plate 400. This ensures that the end face of the rotating drum 106 is always in close contact with the distribution plate 400, preventing liquid leakage.

[0037] Furthermore, the low-wear liquid transfer pump also includes a return plate 200, which is parallel to the swashplate 105 and connected to the end of the drum 106. The return plate 200 has multiple mounting holes distributed circumferentially thereon. Each slipper 500 corresponds to one of the mounting holes and is inserted into its respective hole. The return plate 200 is used to axially press the slippers 500 against the surface of the swashplate 105. During the suction stroke, the return plate 200 can pull back the slippers 500 and the plunger 300, preventing the slippers 500 from detaching from the surface of the swashplate 105 during high-speed rotation.

[0038] Based on the above embodiments, the usage principle and working process of the embodiments of the present invention are as follows: The input shaft 101 is driven to rotate by an external power source, causing the input shaft 101 to drive the rotating drum 106 to rotate synchronously around its own axis (e.g., Figure 4In the X direction, due to the inclined setting of the swashplate 105, the sliding shoes 500 at the ends of the multiple plungers 300 slide along the inclined surface of the swashplate 105 while the rotating drum 106 revolves. Guided by the inclined surface, each plunger 300 slides back and forth along the axial direction in the corresponding suction chamber, thereby periodically changing the volume of each suction chamber and realizing the cyclic conversion of liquid suction and liquid compression actions.

[0039] Taking a single plunger 300 as an example, when the plunger 300 rotates from the lowest position to the highest position of the swashplate 105, it is the hydraulic stroke. The inclined surface of the swashplate 105 pushes the slipper 500, causing the plunger 300 to gradually retract into the suction chamber against the elastic force of the compression spring 302, compressing the liquid in the suction chamber and increasing the liquid pressure in the suction chamber. The high-pressure liquid is discharged from the outlet 1044 through the outlet hole 401 and the outlet chamber 1043, completing the hydraulic process. Figure 11 As shown, at this time, the plunger 300 corresponds to the lowest position of the swashplate 105, the first branch hole 3031 is connected to the first distribution cavity 501, and the second branch hole 3032 is connected to the second distribution cavity 502. Figure 12 As shown, the plunger 300 is at a certain position during the hydraulic stroke. At this time, the plunger 300 and the slipper 500 rotate relative to each other. The first branch hole 3031 is connected to the first distribution chamber 501, and the second branch hole 3032 is offset from the second distribution chamber 502. The high-pressure liquid in the suction chamber enters the first balance chamber 504 sequentially through the inner cavity 301, the through hole 303, and the first branch hole 3031. In the first balance chamber 504, a reverse hydraulic pressure is generated in the opposite direction to the ball head clamping force, thereby counteracting the excessive clamping force of the ball head on the inner wall of the ball socket 5001. Moreover, the first auxiliary damping hole 5061, with its small damping value, allows the pressure in the first balance chamber 504 to respond quickly to the pressure changes in the suction chamber and provide a balancing force in a timely manner.

[0040] When the plunger 300 rotates from the highest position to the lowest position of the swashplate 105, it is the liquid suction stroke. The compression spring 302 releases its elastic potential energy, pushing the plunger 300 outward from the suction chamber, causing the volume of the suction chamber to gradually increase. This reduces the pressure inside the suction chamber, creating a negative pressure. At this time, the liquid at the inlet 1042 is drawn into the suction chamber through the inlet chamber 1041 and the inlet hole 402, completing the liquid suction process. Figure 13 As shown, the plunger 300 corresponds to the highest position of the swashplate 105, the first branch hole 3031 is connected to the first distribution cavity 501, and the second branch hole 3032 is connected to the second distribution cavity 502. Figure 14As shown, the plunger 300 is in a certain position during the suction stroke, and the plunger 300 and the slipper 500 rotate relative to each other. At this time, the first branch hole 3031 is offset from the first distribution chamber 501, and the second branch hole 3032 remains connected to the second distribution chamber 502. Due to the negative pressure in the suction chamber, the liquid in the second balance chamber 503 is drawn into the suction chamber in sequence through the second distribution chamber 502, the second branch hole 3032, the through hole 303, and the inner chamber 301 under the action of pressure difference. This reduces the liquid pressure in the second balance chamber 503, thereby counteracting the separation force generated by the negative pressure in the suction chamber on the ball head, preventing the ball head from separating from or impacting the ball socket 5001. In addition, the second auxiliary damping hole 5051 maintains a stable pressure change in the second balance chamber 503 with its large damping value, avoiding balance failure or seal damage due to excessive pressure relief.

[0041] Meanwhile, during the hydraulic stroke, the high-pressure liquid in the suction chamber also enters the third balance chamber 201 between the slipper 500 and the swashplate 105 through the inner cavity 301, through hole 303, and main damping hole 202 in sequence. Hydraulic support force is formed in the third balance chamber 201, reducing the direct contact wear between the slipper 500 and the swashplate 105.

[0042] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0043] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the appended claims.

Claims

1. A low-wear liquid delivery pump characterized by, include: The housing contains an input shaft. The rotating drum is coaxially mounted on the input shaft and can rotate synchronously around its own axis with the input shaft. It has multiple suction chambers distributed circumferentially inside. The plunger is configured to correspond one-to-one with the suction chamber and can slide along the axial direction of the input shaft in the suction chamber, thus having a liquid pressure stroke and a liquid suction stroke; the plunger has an internal flow channel that communicates with the suction chamber; the end of the plunger away from the suction chamber is provided with a ball head, and the ball head has a first branch hole and a second branch hole, both of which communicate with the internal flow channel. A swashplate is inclinedly mounted on the housing and sleeved on the input shaft. Multiple slippers abut against its inclined surface, with each slipper corresponding to a plunger. Each slipper has a ball socket, and the ball head is ball-hinged into the ball socket. The inner surface of the ball socket is provided with an annular and independent first and second balance chambers. The second balance chamber is located away from the swashplate relative to the first balance chamber, and the axes of both the first and second balance chambers are perpendicular to the swashplate. When the plunger is in the hydraulic stroke, the second branch hole is not connected to the second balance chamber, while the first branch hole is connected to the first balance chamber. The liquid in the suction chamber enters the first balance chamber sequentially through the internal flow channel and the first branch hole to balance the positive pressure on the ball head. When the plunger is in the suction stroke, the first branch hole is not connected to the first balance chamber, while the second branch hole is connected to the second balance chamber. The liquid in the second balance chamber enters the suction chamber sequentially through the second branch hole and the internal flow channel to balance the negative pressure on the ball head.

2. A low wear, liquid transfer pump in accordance with claim 1, wherein, The inner surface of the ball socket is further provided with a first distribution cavity and a second distribution cavity. The first distribution cavity is connected to the first balance cavity, and the second distribution cavity is connected to the second balance cavity. During the rotation of the drum, the plunger will be at the lowest and highest positions of the swashplate, respectively. At the lowest or highest position, the first branch hole is connected to the first distribution cavity, and the second branch hole is connected to the second distribution cavity. The plunger moves from the lowest position to the highest position during the hydraulic stroke. During this process, the first branch hole is connected to the first distribution cavity, and the second branch hole is offset from the second distribution cavity. The plunger moves from the highest position to the lowest position during the liquid suction stroke. During this process, the first branch hole is offset from the first distribution chamber, and the second branch hole is connected to the second distribution chamber.

3. A low wear, liquid transfer pump in accordance with claim 2, wherein, The slipper is provided with a first flow orifice and a second flow orifice, the extension directions of the first flow orifice and the second flow orifice are both perpendicular to the swashplate; the slipper is also provided with a first inclined hole and a second inclined hole, the first inclined hole connects the first distribution cavity to the first flow orifice, and the second inclined hole connects the second distribution cavity to the second flow orifice; a first secondary damping orifice is provided between the first flow orifice and the first balance cavity, the first secondary damping orifice is used to limit the flow rate between the first flow orifice and the first balance cavity, and a second secondary damping orifice is provided between the second flow orifice and the second balance cavity, the second secondary damping orifice is used to limit the flow rate between the second flow orifice and the second balance cavity.

4. The low wear, liquid transfer pump of claim 3, wherein, The damping value of the first damping orifice is less than the damping value of the second damping orifice.

5. The low wear, liquid transfer pump of claim 1, wherein, A compression spring is provided between the plunger and the inner wall of the suction chamber. The axis of the compression spring is parallel to the axis of the input shaft, and the compression spring has a tendency to extend the plunger out of the suction chamber.

6. The low wear, liquid transfer pump of claim 1, wherein, A third balance chamber is provided between the slipper and the swashplate. A main damping hole perpendicular to the swashplate is provided through the center of the slipper. The internal flow channel includes interconnected through holes and an inner cavity. The through holes are connected to the first branch hole and the second branch hole. The inner cavity is connected to the suction chamber. The liquid in the suction chamber can enter the third balance chamber in sequence through the inner cavity, the through hole, and the main damping hole.

7. The low wear, liquid transfer pump of claim 2, wherein, The housing is equipped with a first end cover and a second end cover at its two ends along the axial direction of the input shaft. The second end cover has a distribution plate on the side facing the rotating cylinder. The distribution plate is coaxial with the input shaft and has an outlet hole and an inlet hole. The outlet hole is connected to the suction chamber corresponding to the plunger in the hydraulic stroke, and the inlet hole is connected to the suction chamber corresponding to the plunger in the suction stroke. The side of the second end cover facing the rotating cylinder has an outlet chamber and an inlet chamber. The outlet chamber is set to correspond to the outlet hole, and the inlet chamber is set to correspond to the inlet hole. The two sides of the second end cover also have an outlet port and an inlet port, respectively. The outlet port is connected to the outlet chamber, and the inlet port is connected to the inlet chamber.

8. A low wear, liquid transfer pump in accordance with claim 7, wherein, Both the liquid outlet chamber and the liquid inlet chamber are arc-shaped.

9. The low wear, liquid transfer pump of claim 7, wherein, A central spring is fitted on the input shaft, and the central spring is located at the center of the rotating drum. The central spring is used to press the rotating drum against the distribution plate.

10. The low wear, liquid transfer pump of claim 1, wherein, It also includes a return plate, which is parallel to the swashplate and connected to the end of the drum. The return plate has multiple mounting holes distributed along its circumference. The slippers correspond one-to-one with the mounting holes and are respectively inserted into the corresponding mounting holes. The return plate is used to press the slippers axially against the surface of the swashplate.

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